<html>
<head>

<title>Groovy Goodness: We Can Handle the Truth</title>

<script language="javascript" src="scripts/shCore.js"></script> 
<script language="javascript" src="scripts/shLegacy.js"></script> 
<script language="javascript" src="scripts/shBrushJava.js"></script> 
<script language="javascript" src="scripts/shBrushXml.js"></script> 
<script language="javascript" src="scripts/shBrushJScript.js"></script> 
<script language="javascript" src="scripts/shBrushGroovy.js"></script> 
<script language="javascript" src="scripts/shBrushPlain.js"></script> 
<script language="javascript" src="scripts/shBrushBash.js"></script> 
 
<link href="styles/reset.css" rel="stylesheet" type="text/css" />
<link href="styles/shCore.css" rel="stylesheet" type="text/css" />
<link type="text/css" rel="stylesheet" href="styles/shThemeRDark.css"/>
<link href="styles/blog.css" rel="stylesheet" type="text/css" />

</head>
<body>

<a href="index.html">Back to index</a>

<h3 class="post-title">Groovy Goodness: We Can Handle the Truth</h3>

<div class="post">
<p>In Groovy 1.7 we can coerse objects to a boolean. We only have to provide the method <code>asBoolean()</code> and return true or false. This means our object can be used in a conditional context without accessing any other methods or properties.</p>
<pre class="brush:groovy">
class User {
    String username
    boolean active

    boolean asBoolean() { 
        active
    }
}

assert new User(username: 'mrhaki', active: true)
assert !new User(username: 'mrhaki', active: false)

// We can also add the asBoolean method with metaClass.
String.metaClass.asBoolean = {
    delegate == /sure/
}
assert !'true'
assert 'sure'
</pre
</div>

<script language="javascript"> 
SyntaxHighlighter.config.bloggerMode = true;
SyntaxHighlighter.config.clipboardSwf = 'scripts/clipboard.swf';
SyntaxHighlighter.defaults['first-line'] = 0;
SyntaxHighlighter.defaults['auto-links'] = false;
SyntaxHighlighter.all();
dp.SyntaxHighlighter.HighlightAll('code');
</script>

</body>
</html>